100
Continue
RFC 9110
The initial part of the request was received and the client may continue sending it.
Common use
Large uploads that use the Expect: 100-continue request header.
Development
HTTP Status Code Explorer
Search HTTP response codes and understand what each status means.
Search HTTP status codes
Search by code, reason phrase, description or common use.
Showing 61 status codes
101
Switching Protocols
RFC 9110
The server agrees to switch to the protocol requested by the client.
Common use
Protocol upgrades, including the HTTP upgrade used during some WebSocket handshakes.
102
Processing
RFC 2518
The server received the request and is still processing it.
Common use
Long-running WebDAV operations.
103
Early Hints
RFC 8297
The server sends preliminary headers before the final response.
Common use
Preloading assets while the final page response is still being prepared.
200
OK
RFC 9110
The request completed successfully.
Common use
Successful page loads, API reads and general request responses.
201
Created
RFC 9110
The request succeeded and created a new resource.
Common use
Successful POST requests that create database or API resources.
202
Accepted
RFC 9110
The request was accepted, but processing has not completed.
Common use
Asynchronous jobs, background exports and queued operations.
203
Non-Authoritative Information
RFC 9110
The response metadata was modified by an intermediary.
Common use
Proxies or gateways that transform upstream response information.
204
No Content
RFC 9110
The request succeeded and there is no response body.
Common use
Successful updates, deletions or actions that require no returned data.
205
Reset Content
RFC 9110
The request succeeded and the client should reset its document view.
Common use
Submitting a form that should be cleared after completion.
206
Partial Content
RFC 9110
The response contains only the requested byte range.
Common use
Media streaming, resumable downloads and range requests.
207
Multi-Status
RFC 4918
The response contains statuses for multiple independent operations.
Common use
WebDAV batch operations.
208
Already Reported
RFC 5842
Members of a WebDAV binding were already included earlier in the response.
Common use
Avoiding duplicate enumeration in WebDAV responses.
226
IM Used
RFC 3229
The server returned a representation after applying instance manipulations.
Common use
Delta encoding and transformed resource representations.
300
Multiple Choices
RFC 9110
Multiple representations or destinations are available.
Common use
Presenting several possible resources for the client to choose from.
301
Moved Permanently
RFC 9110
The resource has a new permanent URL.
Common use
Permanent URL migrations and canonical redirects.
302
Found
RFC 9110
The resource is temporarily available at another URL.
Common use
Temporary redirects and authentication flows.
303
See Other
RFC 9110
The client should retrieve another resource using GET.
Common use
Redirecting after form submission to prevent duplicate POST requests.
304
Not Modified
RFC 9110
The cached representation is still valid.
Common use
Conditional requests using ETag or Last-Modified headers.
305
Use Proxy
RFC 9110
The response indicates that a proxy should be used.
Common use
Deprecated legacy proxy behavior.
307
Temporary Redirect
RFC 9110
The resource is temporarily elsewhere and the request method must be preserved.
Common use
Temporary redirects where POST, PUT or another method must remain unchanged.
308
Permanent Redirect
RFC 9110
The resource moved permanently and the request method must be preserved.
Common use
Permanent API or site redirects that must preserve the HTTP method.
400
Bad Request
RFC 9110
The server cannot process the request because it is malformed.
Common use
Invalid JSON, missing syntax or malformed request parameters.
401
Unauthorized
RFC 9110
Valid authentication credentials are required.
Common use
Missing, expired or invalid access tokens and credentials.
402
Payment Required
RFC 9110
The request cannot proceed because payment is required.
Common use
Reserved status sometimes used by paid APIs and billing systems.
403
Forbidden
RFC 9110
The server understands the request but refuses to authorize it.
Common use
Authenticated users lacking the necessary role or permission.
404
Not Found
RFC 9110
The requested resource could not be found.
Common use
Missing pages, API routes or resource identifiers.
405
Method Not Allowed
RFC 9110
The resource exists but does not support the request method.
Common use
Sending POST to a read-only endpoint or GET to an action-only route.
406
Not Acceptable
RFC 9110
The server cannot produce a representation accepted by the client.
Common use
Unsupported Accept header media types or languages.
407
Proxy Authentication Required
RFC 9110
Authentication with an intermediary proxy is required.
Common use
Corporate or controlled proxies requiring credentials.
408
Request Timeout
RFC 9110
The server stopped waiting for the request to complete.
Common use
Slow or interrupted request uploads and inactive connections.
409
Conflict
RFC 9110
The request conflicts with the current state of the resource.
Common use
Duplicate records, version conflicts and concurrent updates.
410
Gone
RFC 9110
The resource is intentionally and permanently unavailable.
Common use
Deleted resources that should not be retried or reindexed.
411
Length Required
RFC 9110
The server requires a Content-Length header.
Common use
Endpoints that reject request bodies of unknown length.
412
Precondition Failed
RFC 9110
A condition supplied in the request headers evaluated to false.
Common use
Optimistic concurrency using If-Match or conditional modifications.
413
Content Too Large
RFC 9110
The request body exceeds the size the server accepts.
Common use
Uploads exceeding API, proxy or application size limits.
414
URI Too Long
RFC 9110
The requested URI is longer than the server accepts.
Common use
Oversized query strings or incorrectly encoded data in URLs.
415
Unsupported Media Type
RFC 9110
The request body uses an unsupported content type or encoding.
Common use
Sending XML to a JSON-only endpoint or using an incorrect Content-Type.
416
Range Not Satisfiable
RFC 9110
The requested byte range cannot be provided.
Common use
Download clients requesting bytes outside the size of a file.
417
Expectation Failed
RFC 9110
The server cannot satisfy the expectation in the request headers.
Common use
Unsupported Expect header behavior.
421
Misdirected Request
RFC 9110
The server is not able to produce a response for the target authority.
Common use
Connection reuse or routing problems in HTTP/2 and HTTP/3 environments.
422
Unprocessable Content
RFC 9110
The syntax is valid, but the instructions cannot be processed.
Common use
API validation errors for structurally valid request bodies.
423
Locked
RFC 4918
The target resource is locked.
Common use
WebDAV resources currently protected by an active lock.
424
Failed Dependency
RFC 4918
The request failed because a related operation failed.
Common use
Dependent WebDAV operations and multi-step actions.
425
Too Early
RFC 8470
The server rejects a request that may be vulnerable to replay.
Common use
TLS early-data requests that are unsafe to process before confirmation.
426
Upgrade Required
RFC 9110
The client must switch to another protocol.
Common use
Requiring a supported protocol version or protocol upgrade.
428
Precondition Required
RFC 6585
The server requires the request to be conditional.
Common use
Preventing lost updates by requiring If-Match.
429
Too Many Requests
RFC 6585
The client exceeded a rate or usage limit.
Common use
API throttling, login protection and resource quotas.
431
Request Header Fields Too Large
RFC 6585
The request headers are too large for the server to process.
Common use
Oversized cookies, authentication headers or accumulated metadata.
451
Unavailable For Legal Reasons
RFC 7725
Access is denied because of a legal demand or restriction.
Common use
Resources blocked due to court orders or regulatory requirements.
500
Internal Server Error
RFC 9110
The server encountered an unexpected condition.
Common use
Unhandled exceptions and generic backend failures.
501
Not Implemented
RFC 9110
The server does not support the functionality required by the request.
Common use
Unsupported HTTP methods or unfinished server capabilities.
502
Bad Gateway
RFC 9110
A gateway received an invalid response from an upstream server.
Common use
Reverse proxy, load balancer and upstream application failures.
503
Service Unavailable
RFC 9110
The service is temporarily unable to handle the request.
Common use
Maintenance, overload and temporary dependency outages.
504
Gateway Timeout
RFC 9110
A gateway did not receive an upstream response in time.
Common use
Slow APIs, database timeouts and unavailable upstream services.
505
HTTP Version Not Supported
RFC 9110
The server does not support the HTTP version used by the request.
Common use
Clients using an unsupported or disabled protocol version.
506
Variant Also Negotiates
RFC 2295
Content negotiation configuration created a circular reference.
Common use
Misconfigured transparent content negotiation.
507
Insufficient Storage
RFC 4918
The server cannot store the representation needed to complete the request.
Common use
WebDAV storage exhaustion and quota failures.
508
Loop Detected
RFC 5842
The server detected an infinite loop while processing the request.
Common use
Circular WebDAV bindings or recursive server operations.
510
Not Extended
RFC 2774
Additional request extensions are required.
Common use
Legacy extension negotiation mechanisms.
511
Network Authentication Required
RFC 6585
The client must authenticate to gain network access.
Common use
Captive portals on public Wi-Fi networks.
Local HTTP reference
This explorer is a local reference and does not contact, test or inspect external servers.
About this tool
What is HTTP Status Code Explorer?
HTTP status codes are three-digit values returned by servers to describe the result of a request. This explorer groups registered codes by response class and explains their meaning and typical use.
Features
Built for fast developer workflows
- Search by status code, name or description.
- Filter informational, success, redirect and error responses.
- Inspect common uses for each HTTP response.
- Copy individual status codes and reason phrases.
- Browse registered HTTP codes without network requests.
- Use the reference entirely inside your browser.
Frequently asked questions
Questions about HTTP Status Code Explorer
What do the first digits of HTTP status codes mean?
1xx responses are informational, 2xx indicate success, 3xx represent redirection, 4xx indicate client-side request problems and 5xx represent server-side failures.
What is the difference between 401 and 403?
401 indicates that valid authentication credentials are missing or unacceptable. 403 means the server understood the request but refuses to authorize it.
Should an API always return 200?
No. APIs should return the status code that best describes the outcome, such as 201 after creating a resource, 204 when no response body is needed or an appropriate 4xx or 5xx error.
Does this tool make HTTP requests?
No. It is a local reference and does not test or contact external servers.
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